Reactor system including a gas distribution assembly for use with activated species and method of using same

ABSTRACT

A reactor system including a gas distribution assembly and method of using the reactor system are disclosed. The gas distribution assembly includes a gas distribution device, a gas expansion area, and a showerhead plate downstream of the gas distribution device and the expansion area.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Non-provisional of, and claims priority to and the benefit of, U.S. Provisional Patent Application Ser. No. 62/912,511, filed Oct. 8, 2019 and entitled “REACTOR SYSTEM INCLUDING A GAS DISTRIBUTION ASSEMBLY FOR USE WITH ACTIVATED SPECIES AND METHOD OF USING SAME,” which is hereby incorporated by reference herein.

FIELD OF INVENTION

The present disclosure generally relates to an apparatus and a method for manufacturing devices. More particularly, the disclosure relates to reactor systems that use activated species, to components of the systems, and to methods of using the same.

BACKGROUND OF THE DISCLOSURE

Reactor systems are often used during the fabrication of electronic devices, such as semiconductor devices. For several fabrication processes, it may be desirable to form activated species to, for example, allow for desired reactions to occur at relatively low temperatures, compared to temperatures for the desired reactions without the aid of activated species.

Recently, deposition of cobalt and cobalt-containing films has gained interest, because of cobalt's appealing physical, mechanical and electrical properties. For example, use of cobalt, rather than other metals can increase reliability of devices. The cobalt films can have relatively high resistance to electromigration and diffusion, resulting in higher comparative stability, compared to devices formed with other metals, such as copper. In addition, cobalt films can be used to form interconnects in integrated circuits. However, cobalt layers tend to oxidize, which may impact the properties of cobalt layers and/or subsequently deposited layers, such as another metal oxide deposited onto the cobalt. Therefore, for many applications, the cobalt layer is treated before the next deposition steps.

Cobalt oxides can be reduced to cobalt metal using a high-temperature annealing process using hydrogen and/or deuterium gas. The thermal reduction of cobalt oxide to cobalt metal typically requires temperatures above 400° C. Use of a high-temperature annealing process to reduce cobalt oxides can lead to degradation or damage of other layers and/or can change the intrinsic properties of cobalt layers.

Accordingly, improved methods and systems are desired. For example, improved methods and systems suitable for use in the reduction of cobalt oxide to cobalt at lower temperatures are desired.

SUMMARY OF THE DISCLOSURE

Various embodiments of the present disclosure provide improved methods, apparatus, and systems for providing reactive species, such as activated hydrogen species (e.g., hydrogen radicals) and/or other activated species to a surface of a substrate. Exemplary methods and systems can be used to remove carbon-containing material and/or oxygen-containing material from a surface of a substrate and/or reduce a metal oxide, such as cobalt oxide. While the ways in which the various drawbacks of the prior art are discussed in greater detail below, in general, the methods and systems described herein can relatively uniformly distribute activated species across a surface of a substrate.

In accordance with at least one exemplary embodiment of the disclosure, a reactor system includes a first reaction chamber, a first remote plasma unit fluidly coupled to the first reaction chamber, and a gas distribution assembly that receives activated species from the first remote plasma unit. The gas distribution assembly can include a gas distribution device, a gas expansion area, and a showerhead plate downstream of the gas distribution device and the gas expansion area, wherein the gas distribution device distributes the activated species within the gas expansion area. The gas distribution device can include one or more holes and/or one or more radially extending channels to distribute the activated species within the gas expansion area. At least a portion of a surface of the gas distribution assembly can be coated with, for example, aluminum oxide and/or yttrium oxide to preserve the activated species. In accordance with various examples of the disclosure, the showerhead plate includes a first set of holes proximate a perimeter of the showerhead plate and a second set of holes proximate a center of the showerhead plate, wherein a diameter of the first set of holes is greater (or smaller) than a diameter of the second set of holes. Additionally or alternatively, a density of the first set of holes is greater (or smaller) than a density of the second set of holes. In accordance with further aspects of these embodiments, the system further includes a second reaction chamber fluidly coupled to the first remote plasma unit. Additionally or alternatively, the system can include a second reaction chamber and a second remote plasma unit fluidly coupled to the second reaction chamber. The first reaction chamber and the second reaction chamber can share or include a common base. Additionally or alternatively, the first reaction chamber and the second reaction chamber can be coupled to the same exhaust line.

In accordance with at least one other embodiment of the disclosure, a reactor system includes a first reaction chamber, a first remote plasma unit fluidly coupled to the first reaction chamber, a first gas distribution assembly that receives activated species from the first remote plasma unit, a second reaction chamber, and a second gas distribution assembly that receives activated species from the first and/or a second remote plasma unit. The first gas distribution assembly can include a first gas distribution device, a first gas expansion area, and a first showerhead plate downstream of the first gas distribution device and the first gas expansion area, wherein the first gas distribution device distributes the activated species within the first gas expansion area. The second gas distribution assembly can include a second gas distribution device, a second gas expansion area, and a second showerhead plate downstream of the second gas distribution device and the second gas expansion area, wherein the second gas distribution device distributes the activated species within the second gas expansion area. The first reaction chamber and the second reaction chamber can share or include a common base.

Reactor systems in accordance with various embodiments of the disclosure can include a hydrogen source coupled to the first remote plasma unit and/or the second remote plasma unit, an inert or carrier gas source between the first remote plasma unit and the first reaction chamber, and the like.

In accordance with at least another exemplary embodiment of the disclosure, a method of treating a surface of a substrate includes use of a reactor system, such as a reactor system described herein. Exemplary methods can be used to reduce cobalt oxide to cobalt. A power supplied to a remote plasma unit during a method described herein can be between about 500 W and about 5000 W or about 1000 W and about 8000 W or about 2000 W and about 10000 W. An inert gas and a hydrogen-containing gas can be provided to the first remote plasma unit and/or the second remote plasma unit, wherein the hydrogen-containing gas is pulsed to the first (and/or second) remote plasma unit while the inert gas flows continuously to the first (and/or second) remote plasma unit.

In accordance with at least one other embodiment of the disclosure, a structure is formed using a method described herein. The structure can include, for example, a layer of cobalt.

For purposes of summarizing aspects of the disclosure and the advantages achieved over the related art, certain objects and advantages of the invention are described in this disclosure. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the disclosure. Thus, for example, examples of the disclosure can be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

A more complete understanding of the embodiments of the present disclosure may be derived by referring to the detailed description and claims when considered in connection with the following illustrative figures.

FIG. 1 illustrates a reactor system in accordance with at least one embodiment of the disclosure.

FIG. 2 illustrates a reactor system in accordance with at least one embodiment of the disclosure.

FIG. 3 illustrates a reactor system in accordance with at least one embodiment of the disclosure.

FIG. 4 illustrates a portion of a reactor system in accordance with at least one embodiment of the disclosure.

FIG. 5 illustrates a reactor system in accordance with at least one embodiment of the disclosure.

FIGS. 6 and 8-11 illustrate gas distribution assemblies in accordance with exemplary embodiments of the disclosure.

FIG. 7 illustrates a gas distribution device in accordance with further examples of the disclosure.

FIG. 12 illustrates a method in accordance with at least one embodiment of the disclosure.

FIG. 13 illustrates a structure in accordance with at least one embodiment of the disclosure.

It will be appreciated that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of illustrated embodiments of the present disclosure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The description of exemplary embodiments of methods, systems, and apparatus provided below is merely exemplary and is intended for purposes of illustration only; the following description is not intended to limit the scope of the disclosure or the claims. Moreover, recitation of multiple embodiments having stated features is not intended to exclude other embodiments having additional features or other embodiments incorporating different combinations of the stated features.

As set forth in more detail below, exemplary methods, assemblies, and systems described herein can be used in the manufacture of electronic devices, such as semiconductor devices. In particular, exemplary systems can be used to provide activated species (e.g., derived from hydrogen) to a surface of a substrate to, e.g., clean or remove contaminants from the substrate surface and/or reduce metal oxides at reduced temperatures.

Reduced processing temperature may be desired to minimize or reduce degradation or damage of other device layers. Activated species, such as hydrogen radicals generated by remote plasma sources, can enable reduction of materials at relatively low temperatures, such as below 200° C., 250° C. or 300° C. The low temperature treatment facilitates maintaining the integrity and continuity of deposited material and can reduce damage that might otherwise occur—e.g., to other layers. Hydrogen radicals can be used to reduce metal oxide back to metal to produce water as a byproduct. The hydrogen radicals can also be used to clean contaminates, such as carbon, from a surface of a substrate. In addition, hydrogen radicals have relatively low kinetic energy, thereby mitigating substrate damage during a pre-clean or clean process. As set forth herein, various embodiments of the disclosure provide systems and methods to generate activated species, such as hydrogen radicals, and transport the activated species to a substrate—e.g., for a surface treatment to remove oxide and/or other contaminants and/or to reduce material on the substrate surface. Various examples provide systems with two or more reaction chambers with shared components, which allows for a reduced cost of ownership, compared to other systems.

As used herein, the term structure can include a substrate and a layer. A structure can form part of a device, such as a device as described herein. Structures can undergo further processing, such as deposition, etch, clean, and the like process steps to form a device.

As used herein, the term substrate can refer to any underlying material or materials upon which a layer can be deposited. A substrate can include a bulk material, such as silicon (e.g., single-crystal silicon) or other semiconductor material, and can include one or more layers, such as native oxides or other layers, overlying or underlying the bulk material. Further, the substrate can include various topologies, such as recesses, lines, and the like formed within or on at least a portion of a layer and/or bulk material of the substrate. By way of particular examples, a substrate may comprise one or more materials including, but not limited to, silicon (Si), germanium (Ge), germanium tin (GeSn), silicon germanium (SiGe), silicon germanium tin (SiGeSn), silicon carbide (SiC), or a group III-V semiconductor material, such as, for example, gallium arsenide (GaAs), gallium phosphide (GaP), or gallium nitride (GaN). In some embodiments, the substrate may comprise one or more dielectric materials including, but not limited to, oxides, nitrides, or oxynitrides. For example, the substrate may comprise a silicon oxide (e.g., SiO₂), a metal oxide (e.g., Al₂O₃), a silicon nitride (e.g., Si₃N₄), or a silicon oxynitride. In some embodiments of the disclosure, the substrate may comprise an engineered substrate wherein a surface semiconductor layer is disposed over a bulk support with an intervening buried oxide (BOX) disposed therebetween. Patterned substrates can include features formed into or onto a surface of the substrate; for example, a patterned substrate may comprise partially fabricated semiconductor device structures, such as, for example, transistors and/or memory elements. In some embodiments, the substrate may contain monocrystalline surfaces and/or one or more secondary surfaces that may comprise a non-monocrystalline surface, such as a polycrystalline surface and/or an amorphous surface. Monocrystalline surfaces may comprise, for example, one or more of silicon, silicon germanium, germanium tin, germanium, or a III-V material. Polycrystalline or amorphous surfaces may include dielectric materials, such as oxides, oxynitrides, or nitrides, such as, for example, silicon oxides and silicon nitrides. In some cases, the substrate includes a layer comprising a metal, such as copper, cobalt, and the like.

As used herein, the term film can refer to any continuous or non-continuous structures and material, such as material deposited by the methods disclosed herein. For example, a film can include 2D materials or partial or full molecular layers or partial or full atomic layers or clusters of atoms and/or molecules. A film can include material with pinholes, but still be at least partially continuous. The terms film and layer can be used interchangeably.

In this disclosure, gas can include vaporized solid and/or liquid and may be constituted by a single gas or a mixture of gases, depending on the context.

Turning now to the figures, FIG. 1 illustrates a system 100 in accordance with exemplary embodiments of the disclosure. System 100 includes a reactor 102, including a reaction chamber 104; a gas distribution assembly 106, including a gas distribution device 108, a gas expansion area 110, and a showerhead plate 112; a substrate support 114; a remote plasma unit (RPU) 116; a first gas source 118; a second gas source 120; a third gas source 122; and a controller 124. System 100 and other systems, as well as methods, described herein can provide extended lifetimes to activated species (e.g., hydrogen radicals) within a reactor and/or a gas distribution apparatus or assembly of a reactor and/or can provide more uniform distribution and/or desired distribution of the activated species.

Susceptor or substrate support 114 can be stationary and can be configured to receive lift pins 136, 138. Susceptor 114 can include one or more heaters 134 and/or one or more conduits for cooling fluid.

Gas distribution assembly 106 is coupled to RPU 116 and receives activated species from RPU 116, distributes the activated species within gas expansion area 110 and provides the activated species to a surface of a substrate 126 via showerhead plate 112. As discussed in more detail below, gas distribution assembly 106, gas expansion area 110, and showerhead plate 112 can be used to distribute the activated species in a desired manner to provide, for example, a desired amount, flowrate, or flux of the activated species to areas on a substrate 126 surface. FIGS. 6-11, described in more detail below, illustrate exemplary gas distribution assemblies and parts thereof suitable for use in connection with examples of the disclosure, including system 100 and other systems described herein.

Gas source 118 can include any suitable gas, such as an inert gas. By way of examples, gas source 118 can include one or more of argon, helium, or neon. Gas source 120 can include any suitable gas. By way of examples, gas source 120 can include one or more of nitrogen, oxygen, water vapor. Gas source 122 can include any suitable gas, such as an active gas. By way of examples, gas source 122 can include one or more of hydrogen and ammonia. System 100 can also include a source 142, which can include, for example, a dilute gas, a carrier gas, and/or an inert gas. The gas from source 142 can be delivered to the reaction chamber downstream of RPU 116 to improve the delivery efficiency and uniformity of activated species.

Controller 124 can be configured to perform various functions and/or steps as described herein. Controller 124 can include one or more microprocessors, memory elements, and/or switching elements to perform the various functions. Although illustrated as a single unit, controller 124 can alternatively comprise multiple devices. By way of examples, controller 124 can be used to control gas flow (e.g., by monitoring flow rates and controlling valves 128, 130, 132), motors, and/or control heaters, such as one or more of the heaters 134, and the like). Further, when a system includes two or more reaction chambers, as described in more detail below, the two or more reaction chambers can be coupled to the same/shared controller.

Reaction chamber 104, at least in part, defines a space in which substrate 126 is processed. To increase a lifetime of activated species, such as hydrogen radicals, produced in remote plasma unit 116, reaction chamber 104 or a portion thereof, substrate support 114, gas distribution assembly 106, and/or a transport path 140 can be coated with materials (e.g., as a coating) and/or be formed of bulk ceramic material in order to promote activated species (e.g., hydrogen radical) lifetime. The materials for the coating can include a metal oxide comprising at least one of: anodized aluminum oxide (Al₂O₃); atomic layer deposition (ALD)-formed aluminum oxide; plasma sprayed Al₂O₃; bare aluminum parts with native aluminum oxide; yttrium oxide (Y₂O₃); yttrium oxide stabilized zirconium oxide (YSZ); zirconium oxide (ZrO₂); lanthanum zirconium oxide (LZO); yttrium aluminum garnet (YAG); yttrium oxyfluoride (YOF); a combination of the above materials; or the above substrate doped with other glass phase materials. In some cases, the coating materials can be made with two layers or more. For example, the first layer may be coated with anodized Al₂O₃ and the second layer may be coated with ALD-formed Al₂O₃. The coating may be amorphous phase, crystalline phase, or mixed. The bulk ceramic material may include: aluminum oxide (Al₂O₃); quartz (SiO₂); zirconium oxide (ZrO₂); yttrium oxide (Y₂O₃); or yttrium oxide stabilized zirconium oxide (YSZ). In accordance with particular exemplary embodiments of the disclosure, the coating includes a material, such as oxide materials (e.g., metal oxides) that have lower recombination coefficients compared to, for example, metals, and thus can be used to facilitate longer lifetimes of hydrogen radicals in reactor system 100. The metals oxides noted above, such as, Al₂O₃ and Y₂O₃, also exhibit good resistivity to corrosion in the presence of activated halogen (e.g., fluorine-containing) gases. These ceramic materials, particularly Al₂O₃, are relatively inexpensive, and can be coated on large machining parts with different manufacturing methods. A conformal, non-porous (e.g., <1% porosity) metal oxide coating works well to extend hydrogen radical lifetimes within a reactor system. One way to achieve the conformal, non-porous coating is to deposit the coating material using atomic layer deposition. In this case, a thickness of the coating can range from about 100 nm to about 1 μm or about 100 nm to about 750 nm or about 250 nm to about 500 nm. A second approach to obtain a smooth, non-porous coating is to form a non-porous anodized (e.g., Al₂O₃) coating having a thickness of about 100 nm to about 1000, about 100 nm to about 750 nm or about 250 nm to about 500 nm.

As noted above, transport path 140 can be coupled to gas source 142. The gas from source 142 may be used to facilitate transport efficiency of the desired intermediate reactive species. In some cases, transport path 140 does not include an orifice to restrict flow rate, which may be present in other systems. Transport path 140 can, in some cases, be cooled—e.g., using water cooling.

Remote plasma unit 116 generates activate species (e.g., radicals) from one or more source gases (e.g., one or more gases from first gas source 118, second gas source 120, and/or third gas source 122). The generated radicals then enter the reaction chamber 104 through gas distribution assembly 106 and then flow onto substrate 126. The remote plasma source may include: a toroidal style ICP and/or CCP source or a coil style ICP source driven by different RF frequencies, such as a 100 kHz, 400 kHz, 2 MHz, 13.56 MHz, 60 MHz, 160 MHz and/or 2.45 GHz microwave source. By way of particular examples, remote plasma unit 116 can be or comprise a Paragon H* remote plasma unit from MKS Instruments.

FIG. 2 illustrates another reactor system 200 in accordance with at least one embodiment of the disclosure. Reactor system 200 includes a first reactor 202, a second reactor 204, a first RPU 206, a second RPU 208, first gas source 210, second gas source 212, third gas source 214, fourth gas source 216, a vacuum source 218, and a controller 220.

Reactors 202, 204 can be similar to reactor 102. Reactor 202 can include a reaction chamber 222, a substrate support 224, and a gas distribution assembly 226. Similarly, reactor 204 can include a reaction chamber 228, a substrate support 230, and a gas distribution assembly 232. System 200 can also include a first transport path 234 below first RPU 206, a second transport path 236 below RPU 208, and a shared transport path 235. RPU 206 and RPU 208 can be the same or similar to RPU 116.

Reactor system 200 can be used to, for example, process substrates in reaction chambers 222 and 228 at the same time. RPU 206 and RPU 208 are configured to provide activated species to the respective reactors 202, 204 through relatively short transport paths 234 and 236, respectively. Reactor system 200 or portions thereof can include the same or similar coating as described above. Further, one or more of transport paths 234, 236 can be coupled to a gas source, such as gas source 142, described above, which can be shared by reactors 202, 204.

First gas source 210, second gas source 212, and/or third gas source 214 can be the same or similar to corresponding gas sources discussed above in connection with FIG. 1. Fourth gas source 216 can include any of the gases described in connection with first-third gas sources. In accordance with one example, fourth gas source 216 includes a surface seasoning gas, such as oxygen or water vapor. As illustrated, first gas source 210, second gas source 212, third gas source 214, and/or fourth gas source 216 can be shared between RPU 206 and RPU 208 and/or between reactor 202 and reactor 204. In some cases, flowrates of the respective gases can be controlled using a shared flow controller.

As illustrated in FIG. 2, reactor 202 and reactor 204 include a common body or base 238, which can be covered with a common insulating material. System 200 can include one or more heaters (e.g., cartridge) and/or cooling channels 240 embedded within body 238, which can be used to control a temperature of the chambers of both reactor 202 and reactor 204.

Reactor system 200 also includes a shared exhaust assembly 242, including a shared isolation valve, a shared pressure control valve (PCV) valve and controller 246 and/or a shared pressure sensor 248. Exhaust assembly 242 can be coupled to vacuum source 218, such as one or more vacuum pumps.

Shared PCV valve and controller 246 can control a chamber pressure, with a specified mass flow condition, so that pressure in RPU 206 and RPU 208 can also be controlled.

Controller 220 can be the same or similar to controller 124, except controller 220 can control components of one or both reactors 202, 204, RPU 206, RPU 208, as well as shared components of exhaust assembly 242.

FIG. 3 illustrates another reactor system 300 in accordance with at least one embodiment of the disclosure. Reactor system 300 includes a first reactor 302, a second reactor 304, an RPU 306, a first gas source 210, a second gas source 212, a third gas source 214, a fourth gas source 216, a vacuum source 218, and a controller 320.

Similar to reactor system 200, reactor system 300 can be used to process substrates in reaction chambers 310 and 312 at the same time. RPU 306 is configured to provide activated species to the respective reactors 302, 304 through (e.g., T-shaped) partially shared path 314. Path 314 can be coupled to a gas source, such as gas source 142, described above. Reactor 300 or portions thereof can include the same or similar coating as described above. In the illustrated example, RPU 306 is shared by two reactors 302, 304, and a single shared gas delivery system 308, which includes gas sources 210-216, and is fluidly connected to RPU 306—e.g., via valves 250-256. Additionally or alternatively, gas sources 210-216, as well as other gas sources described herein, can share common mass or volume flow controllers and/or gas delivery lines, or portions thereof. Further, systems as described herein can include common electrical cabinets that can be shared by two or more reactors.

Reactors 302, 304 can be the same as or similar to reactors 202, 204 and can include the same or similar components. RPU 306 can be the same or similar to RPU 116, RPU 206, or RPU 208.

Shared PCV valve and controller 246 can control a chamber pressure, with a specified mass flow condition, so that pressure in RPU 306 can also be controlled.

Controller 320 can be the same or similar to controller 220, except controller 320 can control components of one or both reactors 302, 304, shared RPU 306, as well as shared components of exhaust assembly 242.

FIG. 4 illustrates a top cut-away view of reactor system 200 and/or reactor system 300. As illustrated, reactor systems 200, 300 can include a common gate valve 402. Reactor systems 200, 300 can also include adaptors 404, 406 interposed between gate valve 402 and a substrate handling chamber, not illustrated.

FIG. 5 illustrates a system 500 in accordance with another example of the disclosure. System 500 includes a load/unload station 502, a substrate handling chamber 504, a first reactor system 506, and a second reactor system 508.

Load/unload station 502 can be used to stage one or more substrates 510 for processing. Substrates 510 can be loaded into cassettes 512 and indexed for processing.

Substrate handling chamber 504 can be used to transport substrates 510 to/from reactor system 506 and/or reactor system 508. In the illustrated example, a dual end effector 514 is used to transport two substrates at a time between load/unload station 502 and reactor systems 506, 508 and/or between reactor systems 506, 508.

Reactor system 506 can be the same or similar to reactor system 200 or 300. Reactor system 508 can include, for example, deposition chambers, etch chambers, clean chambers, or additional reaction chambers as described herein. By way of examples, reactor system 508 can be used to deposit other layer(s), such as cobalt, aluminum oxide, or the like, e.g., using ALD, CVD, or the like. Reactor system 508 can include a source 516, including a vessel 518 and precursors. Reactor system 506 can be used to clean a surface of a substrate and/or reduce metal oxides on the surface of the substrate before or after processing in reactor system 508. Reactor system 508 or another reactor system can include, for example, a cobalt deposition system or an aluminum oxide deposition system. The deposition systems can include one or more vessels including one or more precursors.

FIGS. 6 and 8-11 illustrate gas distribution assemblies 600, 800, 900, 1000, and 1100 in accordance with exemplary embodiments of the disclosure. As set forth in more detail below, gas distribution assemblies 600, 800, 900, 1000, and 1100 can be similar to each other, with varying designs of a showerhead plate. Gas distribution assemblies 600, 800, 900, 1000, and 1100 can be used in connection with, for example, any of reactor systems 100, 200, 300, and 500, and can be used to further facilitate longevity of activated species, such as hydrogen radicals within the respective assemblies and within the respective reactor systems (e.g., across a substrate surface within a reaction chamber of the reactor system) and/or to provide desired distribution profiles of the activated species.

FIG. 6 illustrates a gas distribution assembly 600, which includes a gas distribution device 602, a gas expansion area 604, a showerhead plate 606, and a top section 608.

In operation, one or more gases are received at an inlet 610 of top section 608 and are dispersed within gas distribution device 602 and gas expansion area 604 that is formed between top section 608 and showerhead plate 606. The gas(es) are then distributed to a substrate that resides beneath gas distribution assembly 600.

Top section 608 can be or comprise a plate. The plate can be formed of, for example, aluminum or other suitable material. One or more surfaces, e.g., surface 612 of top section 608, can be coated with a material, such as a coating as described above.

Showerhead plate 606 can also be or comprise a plate. The plate can be formed of, for example, aluminum and/or nickel or other suitable material. One or more surfaces, e.g., surface 614 of showerhead plate 606, can be coated with a material, such as a coating as described herein. Showerhead plate 606 includes a plurality of holes 616 through which gas can travel from gas expansion area 604 to a substrate surface. Holes 616 can be distributed uniformly and/or be of about the same size, or may be in other configurations, as described in more detail below.

Gas distribution device 602 can be used to facilitate a more even distribution of activated species (e.g., hydrogen radicals) from a remote plasma unit, such as any of the remote plasma units described above. Gas distribution device 602 includes a plurality of gas channels 618, 620 to distribute activated species to a region away from the center of gas distribution assembly 600. As illustrated, gas channels 618, 620 can be generally perpendicular to a flow of gas from inlet 610 and can extend radially and/or perpendicular to the inlet flow. Each gas channel 618, 620 can extend from about 10 percent to about 100 percent or about 20 percent to about 80 percent, or about 40 percent to about 70 percent of a radius or similar dimension of gas expansion area 604. Each gas channel 618, 620 can have a diameter of about 2 mm to about 20 mm, or about 5 mm to about 15 mm, or about 7 mm to about 12 mm. In general, the diameter (or similar cross-sectional dimension) should be large enough to mitigate hydrogen radical recombination. Gas distribution device 602 can include any suitable number of gas channels; for example, gas distribution device 602 can include from about 2 to about 50, about 4 to about 48, or about 10 to about 30 channels. In some cases, to compensate for non-uniformity, due to other factors, such as temperature or the like, gas channels 618, 620 may be non-uniformly distributed and/or sized (e.g., the length and/or diameter of the channels may vary). Gas distribution device 602 can also include a plurality of holes 622 to further facilitate desired distribution of gas and activated species. Gas distribution device 602 can be coupled to top section 608 using a variety of techniques, such as use of fasteners and/or welding.

FIG. 7 illustrates a partial cut-away view of gas distribution device 602. In the illustrated example, gas distribution device 602 includes gas channels 702-720, in addition to gas channels 618, 620 illustrated in FIG. 6. As shown, each gas channel can include one or more holes 622 to allow for desired (e.g., uniform) distribution of gas from inlet 610 to gas expansion area 604.

FIG. 8 illustrates a gas distribution assembly 800 in accordance with additional examples of the disclosure. Gas distribution assembly 800 includes a gas distribution device 802, a gas expansion area 804, a showerhead plate 806, and a top section 808. Gas distribution device 802, gas expansion area 804, and top section 808 can be the same or similar to gas distribution device 602, gas expansion area 604, and top section 608 described above.

Showerhead plate 806 can be similar to showerhead plate 606. As illustrated, showerhead plate 806 includes a first set of holes 810 proximate a perimeter of showerhead plate 806 and a second set of holes 812 proximate a center of showerhead plate 806, wherein a diameter of the first set of holes is greater than a diameter of the second set of holes. By way of examples, a diameter or similar cross-sectional area of first set of holes 810 can be about 1.5 mm to about 2 mm, about 1 mm to about 3 mm, or about 1.5 mm to about 5 mm. A diameter or similar cross-sectional area of second set of holes 812 can be about 0.5 mm to about 1 mm, about 1 mm to about 2 mm, or about 1.5 mm to about 3 mm. In at least some cases, a distribution of activated species was greatly improved using first set of holes 810 and second set of holes 812 within showerhead plate 806.

FIG. 9 illustrates a gas distribution assembly 900 in accordance with additional examples of the disclosure. Gas distribution assembly 900 includes a gas distribution device 902, a gas expansion area 904, a showerhead plate 906, and a top section 908. Gas distribution device 902, gas expansion area 904, and top section 908 can be the same or similar to gas distribution device 602, gas expansion area 604, and top section 608 described above.

Showerhead plate 906 can be similar to showerhead plate 606. As illustrated, showerhead plate 906 includes a first set of holes 910 proximate a perimeter of showerhead plate 906 and a second set of holes 912 proximate a center of showerhead plate 906, wherein a diameter of the second set of holes 912 is greater than a diameter of the first set of holes 910. By way of examples, a diameter or similar cross-sectional area of first set of holes 910 can be about 0.2 mm to about 1 mm, about 0.5 mm to about 1.5 mm, or about 1 mm to about 2 mm. A diameter or similar cross-sectional area of second set of holes 912 can be about 0.5 mm to about 1 mm, about 1 mm to about 2 mm, or about 1.5 mm to about 3 mm.

FIG. 10 illustrates a gas distribution assembly 1000 in accordance with additional examples of the disclosure. Gas distribution assembly 1000 includes a gas distribution device 1002, a gas expansion area 1004, a showerhead plate 1006, and a top section 1008. Gas distribution device 1002, gas expansion area 1004, and top section 1008 can be the same or similar to gas distribution device 602, gas expansion area 604, and top section 608 described above.

Showerhead plate 1006 can be similar to showerhead plate 606. As illustrated, showerhead plate 1006 includes a first set of holes 1010 proximate a perimeter of showerhead plate 1006 and a second set of holes 1012 proximate a center of showerhead plate 1006, wherein a density (number of holes per unit area) of the first set of holes 1010 is greater than a density of the second set of holes 1012. By way of examples, a density of first set of holes 1010 can be about 1 /cm² to about 2 /cm², about 2 /cm² to about 4 /cm², or about 3 /cm² to about 6 /cm². A density of second set of holes 1012 can be about 0.5 /cm² to about 2 /cm², about 1 /cm² to about 2.5 /cm², or about 1.5 /cm² to about 3 /cm².

FIG. 11 illustrates a gas distribution assembly 1100 in accordance with additional examples of the disclosure. Gas distribution assembly 1100 includes a gas distribution device 1102, a gas expansion area 1104, a showerhead plate 1106, and a top section 1108. Gas distribution device 1102, gas expansion area 1104, and top section 1108 can be the same or similar to gas distribution device 602, gas expansion area 604, and top section 608 described above. Showerhead plate 1106 can be similar to showerhead plate 606. As illustrated, showerhead plate 1106 includes a first set of holes 1110 proximate a perimeter of showerhead plate 1106 and a second set of holes 1112 proximate a center of showerhead plate 1106, wherein a density of the second set of holes 1112 is greater than a density of the first set of holes 1110. By way of examples, a density of first set of holes 1110 can be about 0.5 /cm² to about 2 /cm², about 1 /cm² to about 2.5 /cm², or about 1 /cm² to about 3 /cm². A density of second set of holes 1112 can be about 1 /cm² to about 2 /cm², about 2 /cm² to about 4 /cm², or about 3 /cm² to about 6 /cm².

FIG. 12 illustrates an exemplary method 1200 in accordance with examples of the disclosure. Method 1200 includes the steps of striking a plasma in an RPU (step 1202), providing an active gas to the RPU (step 1204), providing activated species to a substrate (step 1206), treating the surface of the substrate (step 1208), and purging the reaction chamber (step 1210).

During step 1202, a plasma is created in a RPU, such as one or more of RPU 116, 206, 208, and/or 306. The plasma can be created by flowing an inert, e.g., noble, gas to the RPU and providing power to the RPU. Exemplary inert gases include argon. Exemplary power levels and frequencies are provided above.

During step 1204, an active gas is provided (e.g., pulsed) to the RPU. Exemplary active gases include hydrogen, ammonia. During this step, activated species, such as radicals, are produced within the RPU. The activated species can be pulsed to the reaction chamber. The inert gas can flow continuously to the RPU during steps 1202-1210.

During steps 1206 and 1208, the activated species produced during step 1204 react with a surface of the substrate. The reactions can include cleaning (e.g., removing carbon residue from the substrate surface) and/or reduction (e.g., reducing a metal oxide to a metal). By way of particular examples, the reactions can include:

CoO+2H*=>Co+H₂O

C+H*=>C_(x)H_(y)(g)

A temperature of a substrate during steps 1206 and 1208 can be greater than 200° C., or about 150° C. to about 300° C., or about 200° C. to about 350° C. Additionally or alternatively, the reaction chamber can be heated to a temperature greater than 100° C., or about 80° C. to about 150° C., or about 100° C. to about 250° C. A pressure within the reaction chamber can be about 0.1 torr to about 3 torr, or about 0.5 torr to about 10 torr, or about 1 torr to about 50 torr. A foreline—e.g., of a shared exhaust line, can be heated to a temperature greater than 120° C., or about 80° C. to about 120° C., or about 100° C. to about 180° C. to prevent or mitigate condensation in the reactor system.

During step 1210, the reaction chamber can be purged—e.g., by continuing to flow the inert gas through the RPU.

FIG. 13 illustrates a structure 1300 in accordance with another example of the disclosure. Structure 1300 includes a substrate 1302 and a layer 1304. Substrate 1302 can be or include any of the substrate materials described above. In some cases, substrate 1302 can include a layer of copper. Layer 1304 can include, for example, a metal. By way of particular examples, layer 1304 can comprise cobalt, such as a layer of cobalt metal. Layer 1304 can be formed using a reactor system and/or a method as described herein. Structure 1300 can include additional layers overlying layer 1304, such as metal oxides (e.g., aluminum oxide), silicon oxides (e.g., SiOC), and the like. Although exemplary embodiments of the present disclosure are set forth herein, it should be appreciated that the disclosure is not so limited. For example, although the system and method are described in connection with one or two RPU units, any suitable number of RPU units can be included in a reactor system—e.g., two or more RPU can be coupled to one or more reaction chambers. Various modifications, variations, and enhancements of the system and method set forth herein may be made without departing from the spirit and scope of the present disclosure. 

We claim:
 1. A reactor system comprising: a first reaction chamber; a first remote plasma unit fluidly coupled to the first reaction chamber; and a gas distribution assembly that receives activated species from the first remote plasma unit, wherein the gas distribution assembly comprises: a gas distribution device; a gas expansion area; and a showerhead plate downstream of the gas distribution device and the expansion area, and wherein the gas distribution device distributes the activated species within the gas expansion area.
 2. The reactor system of claim 1, wherein the gas distribution device comprises one or more holes.
 3. The reactor system of claim 1, wherein the gas distribution device comprises one or more radially extending channels.
 4. The reactor system of claim 1, wherein at least a portion of a surface of the gas distribution assembly is coated with aluminum oxide.
 5. The reactor system of claim 4, wherein a thickness of the aluminum oxide is between about 100 nm and about 1 μm.
 6. The reactor system of claim 1, wherein at least a portion of a surface of the gas distribution assembly is coated with yttrium oxide.
 7. The reactor system of claim 6, wherein a thickness of the yttrium oxide is between about 100 nm and about 1 μm.
 8. The reactor system of claim 1, wherein the showerhead plate comprises a first set of holes proximate a perimeter of the showerhead plate and a second set of holes proximate a center of the showerhead plate, wherein a diameter of the first set of holes is greater than a diameter of the second set of holes.
 9. The reactor system of claim 1, further comprising a second reaction chamber fluidly coupled to the first remote plasma unit.
 10. The reactor system of claim 1, further comprising a second reaction chamber and a second remote plasma unit fluidly coupled to the second reaction chamber.
 11. The reactor system of claim 9, wherein the first reaction chamber and the second reaction chamber comprise a common base.
 12. The reactor system of claim 9, further comprising an exhaust line, wherein the first reaction chamber and the second reaction chamber are fluidly coupled to the exhaust line.
 13. The reactor system of claim 12, wherein the exhaust line comprises a pressure sensor and a control valve.
 14. The reactor system of claim 1, further comprising a hydrogen source coupled to the first remote plasma unit.
 15. The reactor system of claim 1, further comprising a gas source coupled to the reactor system between the first remote plasma unit and the first reaction chamber.
 16. A method of treating a surface of a substrate using the reactor system of claim
 1. 17. The method of claim 16, wherein the method of treating comprises reducing cobalt oxide.
 18. The method of claim 16, wherein a power of the first remote plasma unit is between about 500 W and about 5000 W or about 1000 W and about 8000 W or about 2000 W and about 10000 W.
 19. The method of claim 16, wherein an inert gas and a hydrogen-containing gas are provided to the first remote plasma unit, wherein the hydrogen gas is pulsed to the first remote plasma unit while the inert gas flows continuously to the first remote plasma unit.
 20. A structure formed using the method of claim
 16. 21. The structure of claim 20 comprising a layer of cobalt.
 22. A reactor system comprising: a first reaction chamber; a first remote plasma unit fluidly coupled to the first reaction chamber; a first gas distribution assembly that receives activated species from the first remote plasma unit, wherein the first gas distribution assembly comprises: a first gas distribution device; a first gas expansion area; and a first showerhead plate downstream of the first gas distribution device and the first gas expansion area, wherein the first gas distribution device distributes the activated species within the first gas expansion area; a second reaction chamber; and a second gas distribution assembly that receives activated species from the first or a second remote plasma unit, wherein the second gas distribution assembly comprises: a second gas distribution device; a second gas expansion area; and a second showerhead plate downstream of the second gas distribution device and the second expansion area, and wherein the second gas distribution device distributes the activated species within the second gas expansion area.
 23. The reactor system of claim 22, wherein the first reaction chamber and the second reaction chamber comprise a common base. 